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Polymerization shrinkage and stress development in amorphous calcium phosphate/urethane dimethacrylate polymeric
J M Antonucci1, W F Regnault, D Skrtic
1Polymers Division, National Institute of Standards and Technology, Gaithersburg, MD 20899.
Journal of Composite Materials
|February 20, 2010
Summary
This study found that replacing 2-hydroxyethyl methacrylate (HEMA) with poly(ethylene glycol) extended urethane dimethacrylate (PEG-U) in dental resins improves vinyl conversion without negatively impacting shrinkage or strength. PEG-U shows promise as a HEMA alternative.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Dental Materials
Background:
- 2-hydroxyethyl methacrylate (HEMA) is a common monomer in dental resins.
- High molecular mass oligomeric poly(ethylene glycol) extended urethane dimethacrylate (PEG-U) is a novel alternative.
- Understanding monomer substitution effects on composite properties is crucial for material development.
Purpose of the Study:
- To investigate the impact of substituting HEMA with PEG-U in urethane dimethacrylate (UDMA) based resins.
- To evaluate the effects on degree of vinyl conversion (DC), polymerization shrinkage (PS), stress development (PSSD), and biaxial flexure strength (BFS) of amorphous calcium phosphate (ACP) composites.
- To assess PEG-U as a potential alternative to HEMA in biomedical applications.
Main Methods:
- Four resin formulations were prepared: UDMA, PEG-U, UDMA/HEMA, and UDMA/PEG-U.
- Zirconia-hybridized amorphous calcium phosphate (ACP) was incorporated into the resins.
- Key properties including DC, PS, PSSD, and BFS were measured for each composite.
Main Results:
- Composites containing PEG-U exhibited an improved degree of vinyl conversion (DC).
- Polymerization shrinkage (PS) and stress development (PSSD) were not adversely affected by PEG-U inclusion.
- Biaxial flexure strength (BFS) remained comparable to HEMA-containing composites.
- The enhanced DC is linked to PEG-U's longer, more flexible structure and higher molecular mass.
Conclusions:
- Poly(ethylene glycol) extended urethane dimethacrylate (PEG-U) can effectively replace 2-hydroxyethyl methacrylate (HEMA) in UDMA-based resins.
- PEG-U offers improved degree of vinyl conversion without compromising critical mechanical properties.
- PEG-U demonstrates significant potential as a substitute for HEMA in dental and biomedical composite applications.
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